James must mix 60 millilitres of 10% solution and 40 millilitres of 50% solution.
Given that, James needs to mix a 10% acid solution with a 50% acid solution to create 100 millilitres of a 26% solution.
Let the acid solution needs to mix with 10% be x ml and the acid solution needs to mix with 50% will be 100 - x ml.
Now,
10% x + 50% ( 100 - x ) = 26% ×100
⇒[tex]\frac{10x}{100} +\frac{50(100-x)}{100}=\frac{2600}{100}[/tex]
⇒10x + 50( 100 - x ) = 2600
⇒10 x + 5000 - 50x = 2600
⇒10 x - 50 x = 2600-5000
⇒-40 x = -2400
⇒x=60
Therefore, James must mix 60 millilitres of 10% solution and 40 millilitres of 50% solution.
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A circle in the xyxyx, y-plane has a center at \left(\dfrac{3}{4\,},\dfrac{1}{2}\right)(
4
3
,
2
1
)left parenthesis, start fraction, 3, divided by, 4, end fraction, comma, start fraction, 1, divided by, 2, end fraction, right parenthesis and a radius that is \dfrac{3}{5}
5
3
start fraction, 3, divided by, 5, end fraction units long. Which of the following is an equation of the circle
The equation of the circle will be (x – 3/4)² + (y – 1/2)² = 9/25. Then the correct option is A.
What is an equation of a circle?A circle can be characterized by its center's location and its radius's length.
Let the center of the considered circle be at the (h,k) coordinate.
Let the radius of the circle be 'r' units.
Then, the equation of that circle would be:
(x – h)² + (y – k)² = r²
We have
(h, k) = (3/4, 1/2)
r = 3 / 5
Then the equation of circle will be
(x – 3/4)² + (y – 1/2)² = (3/5)²
(x – 3/4)² + (y – 1/2)² = 9/25
Then the correct option is A.
The missing options are given below.
A. (x – 3/4)² + (y – 1/2)² = 9 / 25
B. x² + y² = 9/25
C. (x – 3/4)² + (y – 1/2)² = 25 / 9
D. (x – 1/2)² + (y – 3/4)² = 9/25
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Select the solution to the following system of equations:
Answer:
4x+2y=4
3x-y=-7
first one by 3
second by 4
12x+6y=12
12x-4y=-28
subtract
10y=40
y=4
plug in
3x-4=-7
add 4
3x=-3
x=-1
(-1,4)
c
Hope This Helps!!!
Answer: third option
Step-by-step explanation:
There are 2 ways to go about systems of equations normally, and that's elimination and substitution. For this particular problem, I would recommend elimination.
we see the first equation 4x+2y=4
we want to be able to simplify it as much as possible (so it's easier to solve)
so we divide all the terms by 2, giving 2x+y=2.
the second equation can't be simplified, so we set up the elimination method.
2x+y=2
-3x-y=-7
multiplying both equations by 2 and 3, we subtract them and get that y equals 4, which is clearly the answer.
Daran just retired, and has $670,000 to invest. A very safe Certificate of Deposit (CD) account pays 1.5%, while a riskier bond fund pays 8.5% in interest. Daran figures he needs $40,000 a year in interest to live on. How much should he invest in each account to make enough interest while minimizing his risk? Round answers to the nearest dollar.
Answer:
bond: $427,857CD: $242,143Step-by-step explanation:
We can use the given interest rates and the investment and interest amounts to write an equation for the amount of interest Daran needs to earn.
SetupLet b represent the amount Daran should invest in the bond fund (in thousands). Then 670 -x is the amount he will invest in the CD account. The total interest he wants to earn (in thousands) is ...
0.085(b) +0.015(670 -b) = 40
SolutionEliminating parentheses and collecting terms, we have ...
0.07b +10.05 = 40
0.07b = 29.95
b = 427.857
Daran should invest $427,857 in the bond fund and $242,143 in the CD account.
One Scrambled egg contains 95 calories . How many calories are there in 3 scrambled eggs
-------------------------------------------------------------------------------------------------------------
Answer: [tex]\textsf{285 total calories}[/tex]
-------------------------------------------------------------------------------------------------------------
Given: [tex]\textsf{1 egg = 95 calories}[/tex]
Find: [tex]\textsf{Calories in 3 eggs}[/tex]
Solution: In order to determine the total amount of calories in 3 eggs we must multiply the amount of calories in one egg by 3. So we do 95 * 3 which gives us 285 total calories.
Find the coefficient of x^6 in the binomial expansion of (2x + 3)^9
Answer:
145,152
Step-by-step explanation:
So there's actually two things you'll need in this equation. You'll need to use pascals triangle, to find the coefficients, and the binomial theorem to find the degrees.
So in this case you want to find the 9th row of pascals triangle. You could write out the entire 10 rows of pascals triangle to find the 9th row (because the first row is row 0). So to find the nth row you generally will start with 1 as the first term as every single row will start with this number. Now after that you're going to continue "row" amount of times starting with 2 values. One value which I'll name k=0 and the other j=1
Now let's start with what we have {1}, take the previous term and (which will always be 1 in the first case, and then multiply it by (row - k) / j. So in this case k=0, and j=1, row=9. You'll have (1 * (9)) / 1. This gives you 9, which is the second term. So now you have the terms {1, 9}. Now the next iteration add 1 to k and 1 to j. And the previous is now 9. So now you have (9 * (9 - 1)) / 2 = (9 * 8) / 2 = 72 / 2 = 36. Which is the next term. {1, 9, 36}. and then continue this until you have row+1 amount of numbers, or in other words repeat it "row" amount of times, since you already started with 1.
In doing so you will get {1, 9, 36, 84, 126, 126, 84, 36, 9, 1}
Now to use binomial theorem to expand find the degrees. Cause currently we can determine the coefficients, but what about the degrees? So it's as if we have the equation: [tex]1(2x)^a(3)^b+9(2x)^c(3)^d+36(2x)^e(3)^f.....[/tex] and so on until we use up all the numbers in the row. But binomial theorem essentially states that the degrees will expand as such: [tex]C_0a^nb^0+C_1+a^{n-1}b^{0+1}+C_2a^{n-2}b^{0+2}...C_na^{n-n}b^{n}[/tex]. So essentially the degree of a starts at n (in this case 9), and and then from there continues to go down until it reaches 0, while the degree of b starts at 0 (so it's just 1) and continues to go up (by 1) until it reaches n
So expanding it out gives us:
[tex]1(2x)^9(3)^0 + 9(2x)^{9-1}(3)^{0+1}+36(2x)^{9-2}(3)^{0+2}+84(2x)^{9-3}(3)^{0+3}[/tex]... and so on But in this case we really only care about degree six which occurs at 9-3. So let's focus on that
[tex]84(2x)^6(3)^3[/tex]. This evaluates out to [tex]84(64x^6)(27)[/tex] which then evaluates to [tex]145,152x^6[/tex]
Find the critical points of the surface f(x, y) = x3 - 6xy + y3 and determine their nature.
Compute the gradient of [tex]f[/tex].
[tex]\nabla f(x,y) = \left\langle 3x^2 - 6y, -6x + 3y^2\right\rangle[/tex]
Set this equal to the zero vector and solve for the critical points.
[tex]3x^2-6y = 0 \implies x^2 = 2y[/tex]
[tex]-6x+3y^2=0 \implies y^2 = 2x \implies y = \pm\sqrt{2x}[/tex]
[tex]\implies x^2 = \pm2\sqrt{2x}[/tex]
[tex]\implies x^4 = 8x[/tex]
[tex]\implies x^4 - 8x = 0[/tex]
[tex]\implies x (x-2) (x^2 + 2x + 4) = 0[/tex]
[tex]\implies x = 0 \text{ or } x-2 = 0 \text{ or } x^2 + 2x + 4 = 0[/tex]
[tex]\implies x = 0 \text{ or } x = 2 \text{ or } (x+1)^2 + 3 = 0[/tex]
The last case has no real solution, so we can ignore it.
Now,
[tex]x=0 \implies 0^2 = 2y \implies y=0[/tex]
[tex]x=2 \implies 2^2 = 2y \implies y=2[/tex]
so we have two critical points (0, 0) and (2, 2).
Compute the Hessian matrix (i.e. Jacobian of the gradient).
[tex]H(x,y) = \begin{bmatrix} 6x & -6 \\ -6 & 6y \end{bmatrix}[/tex]
Check the sign of the determinant of the Hessian at each of the critical points.
[tex]\det H(0,0) = \begin{vmatrix} 0 & -6 \\ -6 & 0 \end{vmatrix} = -36 < 0[/tex]
which indicates a saddle point at (0, 0);
[tex]\det H(2,2) = \begin{vmatrix} 12 & -6 \\ -6 & 12 \end{vmatrix} = 108 > 0[/tex]
We also have [tex]f_{xx}(2,2) = 12 > 0[/tex], which together indicate a local minimum at (2, 2).
A relish is prepared by the following recipe:
pickles
onions
1000 pounds
500 pounds
900 pounds
75 pounds
5 pounds.
sugar
salt brine
spices
The onions are 85% water, the pickles are 92% water and 1.1% salt, and the salt brine is 88%
water. During processing, 18% of the water originally in the mixture is evaporated out.
What is the weight of relish prepared.
The weight of relish prepared after the evaporation of water is 2,226.02 pounds
Percentagepickles = 1000 poundsonions = 500 poundssugar = 900 poundssalt brine = 75 poundsspices = 5 poundsTotal = 1000 + 500 + 900 + 75 + 5
= 2,480 pounds
pickles are 92% water
= 92/100 × 1000
= 920 pounds
onions are 85% water
= 85/100 × 500
= 425 pounds
salt brine is 88% water
= 88/100 × 75 pounds
= 66 pounds
Total water in the mixture = 920 pounds + 425 pounds + 66 pounds
= 1,411 pounds
Percentage of water evaporated = 18%Amount of water evaporated = 18/100 × 1,411 pounds
= 253.98 pounds
Weight of the relish prepared = 2,480 pounds - 253.98 pounds
= 2,226.02 pounds
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Giving brainliest :)
Answer:
3
Step-by-step explanation:
first find g(-2) by plugging in -2 as x in the g(x) equation
g(-2) = 3(-2)+5
g(-2) = -6+5
g(-2) = -1
then plug that value (-1) as x in the f(x) equation
f(-1) = 4-(-1)^2
f(-1) = 4-1
f(-1) = 3
Can u help me with number 7
Step-by-step explanation:
This triangle is acute! ✅
It is also scalene.
see the picture below
PLEASE HELP!!!
There are many different kinds of numbers (whole numbers, fractions, etc.). Name some different types of numbers. Do you know how to do operations with different types of numbers? What operations do you know how to perform with the different types of numbers?
Answer:
Types of numbers
Natural Numbers - Common counting numbers.
Prime Number - A natural number greater than 1 which has only 1 and itself as factors.
Composite Number - A natural number greater than 1 which has more factors than 1 and itself.
Whole Numbers - The set of Natural Numbers with the number 0 adjoined.
Integers - Whole Numbers with their opposites (negative numbers) adjoined.
Rational Numbers - All numbers which can be written as fractions.
Irrational Numbers - All numbers which cannot be written as fractions.
Real Numbers - The set of Rational Numbers with the set of Irrational Numbers adjoined.
Complex Number - A number which can be written in the form a + bi where a and b are real numbers and i is the square root of -1.
Step-by-step explanation:
If your scientific notation is 2.420 x 10° g (2.420 E 5 g), which direction would you move the decimal point to get the scientific notation converted back to standard notation?
Down
Left
Up
Right
According to scientific notation the decimal point is shifted to the right (option D).
What is scientific notation?Scientific notation is a term to refer to the way of writing numbers based on powers of 10. Generally this tool is used for very large or small values.
According to the above, the number 2,420 x 10⁵ expressed in decimal would look like this:
242000According to the above, it can be inferred that the point is placed in the final right part of the number, that is, it moves to the right.
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Heads, Heads
15
Heads, Tails
11
Tails, Heads
17
Tails, Tails
7
Total
50
Based on your data, what is the experimental probability that the family has two dogs or two cats?
If the family has three pets, what is the theoretical probability that they have three dogs or three cats?
How could you change the simulation to generate data for three pets?
The probability that the family has two dogs or two cats will be 0.5.
How to calculate the probability?From the information, the head represents cats and rte tails represent dogs.
The experimental probability that the family has two dogs or two cats will be:
= (1/2 × 1/2) + (1/2 × 1/2)
= 1/4 + 1/4
= 1/2
= 0.5
Also, the theoretical probability that they have three dogs or three cats is 0.5.
The simulation to generate data for three pets will be to add a new coin and category for the new pet.
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Solve x2 – 5x – 24 = 0 by completing the square
A)
x = –6 and x = –4
B)
x = 6 and x = –4
C)
x = 3 and x = –8
D)
x = –3 and x = 8
The solutions of the equation x² – 5x – 24 = 0 will be 8 and -3. Then the correct option is D.
What is a factorization?It is a method for dividing a polynomial into pieces that will be multiplied together. At this moment, the polynomial's value will be zero.
The quadratic equation is given below.
x² – 5x – 24 = 0
Then the factor of the equation will be
x² – 5x – 24 = 0
x² – 8x + 3x – 24 = 0
x(x – 8) + 3(x – 8) = 0
(x – 8)(x + 3) = 0
x = 8, -3
Then the correct option is D.
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Which rule describes the composition of transformations that maps ΔJKL to ΔJ"K"L"?
The rule that describes the composition of transformations that maps ΔJKL to ΔJ"K"L" is Rotation 0° to 90° and reflection about the x-axis.
What is the transformations rule that was used here?A transformation is a rule that is used to manipulate the position of a point of geometric figure.
Analyzing the figure, rotation of ΔJKL through the angle 90 degrees in a counter-clockwise direction gives us ΔJ'K'L' .
ΔJ"K"L" is been gotten also using ΔJ'K'L' through the refraction of ΔJ'K'L' across the x-axis.
In this case, rule that describes the composition of transformations that maps ΔJKL to ΔJ"K"L" is Rotation 0° to 90° and reflection about the x-axis.
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Answer: C). 90 degree rotation about point 0 composition translation of negative 2 units x, 0 units y
Step-by-step explanation:
What is the area of the parallelogram?
Enter your answer in the box.
mm²
Parallelogram. Left side labeled 21 millimeters. Top side labeled 27 millimeters. A dashed segment perpendicular to the 27 millimeter side is labeled 18 millimeters.
Answer:
486mm²Step-by-step explanation:
The area of a parallelogram is h*b where h is the height/altitude and b is the base.
The base is 27 millimeters and the altitude is 18 millimeters, so we multiply those together.
27*18= 486.
The area of the parallelogram is 486mm²
Hope this helps!
ten selected students took a. altitude test out of the total score of 100 these students scored 60,50,50,70,40,80,65,55,50 and 90 respectively calculate the mean and the mode and the median for the given set of data
Answer:
• mean = 61
• mode = 50
• median = 57.5
Step-by-step explanation:
• The mean is calculated by adding all the values together, and dividing the result by the number of values.
∴ mean = [tex]\frac{60 + 50 + 50 + 70 + 40 + 80 + 65 + 55 + 50 + 90}{10}[/tex]
⇒ mean = [tex]\frac{610}{10}[/tex]
⇒ mean = 61
• The mode of a set of values is the value that is the most common (has highest frequency) among them.
50 is the most common value.
∴ mode = 50
• The median is the middle-value of a set of ordered values.
∴ We have to first rearrange the set:
⇒ 40, 50, 50, 50, 55, 60, 65, 70, 80, 90
Now we need to find the middlemost value:
Since we have 10 values, which is an even number, we have to use the formula:
median = [tex]\frac{(n/2)^{th} \space\ term \space\ + \space\ [(n/2) + 1]^{th} \space\ term }{2}[/tex]
where n is the number of values.
∴ median = [tex]\frac{(10/2)^{th} \space\ term \space\ + \space\ [(10/2) + 1]^{th} \space\ term }{2}[/tex]
⇒ median = [tex]\frac{5^{th} \space\ term \space\ + \space\ 6^{th} \space\ term }{2}[/tex]
The 5th and 6th terms in our ordered series are 55 and 60 respectively.
∴ median = [tex]\frac{55 + 60}{2}[/tex]
⇒ median = 57.5
1) Write four consecutive integers preceding -87?
Answer:
-86,-85,-84,-83 and so on...
Step-by-step explanation:
Use the Number Line
Answer:
-88,-89,-90,-91,-92
Step-by-step explanation:
This table shows rainfall in centimeters for a city in different months the quadratic regression equation that models these data is y=-0.77x^2+6.06x-5.9. Using the model the predicted rainfall for month 11 is about -32.4 centimeters does this prediction make sense why or why not HELP ASAP
Answer:
(a) No; rainfall amounts are positive
Step-by-step explanation:
Rainfall amounts are measured using a gauge that reports the amount as zero when the gauge is empty. Any rainfall adds to the amount in the gauge, so is reported as a positive number. There is no way to remove more rainfall than is in the gauge, so there is no way to have a negative rainfall amount
A prediction of a negative rainfall amount makes no sense, because you can't have a negative amount of rainfall.
Can someone please help me with calculus , i am having so much trouble. Thank you! 12points
1) If the limit [tex]L[/tex] is
[tex]L = \displaystyle \lim_{\Delta x\to0} \frac{\sin\left(\frac\pi3 + \Delta x\right) - \sin\left(\frac\pi3\right)}{\Delta x}[/tex]
then using the hint as well as [tex]\sin\left(\frac\pi3\right)=\frac{\sqrt3}2[/tex] and [tex]\cos\left(\frac\pi3\right)=\frac12[/tex] we have
[tex]\displaystyle L = \lim_{\Delta x\to0} \frac{\sin\left(\frac\pi3\right)\cos(\Delta x) + \cos\left(\frac\pi3\right)\sin(\Delta x) - \sin\left(\frac\pi3\right)}{\Delta x}[/tex]
[tex]\displaystyle L = \sin\left(\frac\pi3\right) \lim_{\Delta x\to0} \frac{\cos(\Delta x) - 1}{\Delta x} + \cos\left(\frac\pi3\right) \lim_{\Delta x} \frac{\sin(\Delta x)}{\Delta x}[/tex]
[tex]L = \dfrac{\sqrt3}2 \times 0 + \dfrac12\times1 = \boxed{\dfrac12}[/tex]
which follows from the well-known limits,
[tex]\displaystyle \lim_{x\to0} \frac{1-\cos(x)}x = 0 \text{ and } \lim_{x\to0} \frac{\sin(x)}x=1[/tex]
Alternatively, if you already know about derivatives, we can identify the limit as the derivative of [tex]\sin(x)[/tex] at [tex]x=\frac\pi3[/tex], which is [tex]\cos\left(\frac\pi3\right)=\frac12[/tex].
2) It looks like you may be using double square brackets deliberately to denote the greatest integer or floor function which rounds the input down to the nearest integer. That is, [tex][\![x]\!][/tex] is the greatest integer that is less than or equal to [tex]x[/tex]. The existence of [tex]L[/tex] depends on the equality of the one-sided limits.
Suppose [tex]3\le x<4[/tex]. Then [tex]2[tex]\displaystyle \lim_{x\to4^-} [\![x - 1]\!] = 2[/tex]
Now suppose [tex]4\le x<5[/tex], so that [tex]3\le x-1 < 4 \implies [\![x-1]\!]=3[/tex] and
[tex]\displaystyle \lim_{x\to4^+} [\![x-1]\!] = 3[/tex]
The one-sided limits don't match so the limit doesn't exist.
Are the arcs below congruent?
113°
A
B
0
H
120⁰
G
OA. Yes, because the central angles are the same.
OB. Yes, because they are both minor arcs.
Answer:
C. no, because the arcs do not have the same measure.
Step-by-step explanation:
for 2 structures to be congruent all the angles need to be the same (and then all the lines must have the same scaling factor between both structures - but that is not relevant here anymore, since the angles are already off).
Which best describes the relationship between the line that passes through the points (-9, -7) and (-12, -2) and the line
that passes through the points (1, 9) and (6, 6)?
A. neither perpendicular nor parallel
B. perpendicular
C. same line
OD. parallel
Answer:
A
Step-by-step explanation:
The equation of the line that passes through the points (-9,-7) and (-12,-2) is
y = -5/3x-22
and
equation of the line that passes through the points (1, 9) and (6, 6) is
y = -3/5x+48/5
clearly it is not the same line,
[tex]\frac{-5}{3}.\frac{-3}{5} \neq -1[/tex] (lines are not perpendicular)
[tex]\frac{-5}{3}\neq \frac{-3}{5}[/tex] (not parallel)
Let g(x) = log7 (x),
find g ¹(0)
Step-by-step explanation:
The derivative of log is
[tex] \frac{d}{dx} ( log_{a}(x) ) = \frac{1}{x \: ln(a) } [/tex]
You can easily derive this using the Change of base rule, and natural log rules
[tex] log_{a}(x) = \frac{ log_{e}(x) }{ log_{e}(a) } = \frac{ ln(x) }{ ln(a) } [/tex]
Next, we differentiate with respect to x.
[tex] \frac{d}{dx} \frac{ ln(x) }{ ln(a) } = \frac{1}{ ln(a) } \times \frac{d}{dx} ln(x) [/tex]
[tex] = \frac{1}{x ln(a) } [/tex]
So back to the topic at hand,.
a=7, so we get
[tex] \frac{1}{x ln(7) } [/tex]
We plug in 0, we would get undefined
Solve for x: -4(3x - 2) = 6x +2
Answer:
x=1/3
Step-by-step explanation:
-4(3x-2)=6x+2
or,-12x+8=6x+2
or,-12x-6x=2-8
or,-18x=-6
or,x=-6/-18
or,x=1/3
PLEASE SEE THE ABOVE PICTURE.
Solve this part please fast
Give the right answers
Step-by-step explanation:
believe it or not, the area of any triangle is
baseline × height / 2
we have here 2 triangles, both with the same baseline (8 cm), but with 2 different heights : 6.5 cm and 4.6 cm.
so, their areas are
8 × 6.5 / 2 = 4 × 6.5 = 26 cm²
8 × 4.6 / 2 = 4 × 4.6 = 18.4 cm²
so, in total, the shaded region is
26 + 18.4 = 44.4 cm²
what is the area of the shaded face of the cylinder is 22m
give your answer to the nearest whole number and give the correct units
The area of the shaded face of the cylinder with the given radius is approximately 1520cm².
This question is incomplete, the missing diagram is uploaded along the answer below.
What is the area of the shaded face of the cylinder?From the diagram, the shaded region is a circle with radius 22 meters.
Area of a circle is expressed as;
A = π × r²
r is radius and π is constant pi ( π = 3.14 )
We substitute our values into the equation above.
A = π × r²
A = 3.14 × (22m)²
A = 3.14 × 484m²
A = 1519.76 ≈ 1520cm²
Therefore, the area of the shaded face of the cylinder with the given radius is approximately 1520cm².
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One number is 2 more than another. The difference between their squares is 24. What are the numbers?
Answer:
5 and 7Step-by-step explanation:
One number is 2 more than another. The difference between their squares is 24. What are the numbers?
(x + 2)² - x² = 24
x² + 4x + 4 - x² = 24
4x + 4 = 24
4x = 20
x = 20 : 4
x = 5
----------------------
5 + 2 = 7
check
(5 + 2)² - 5² = 24
49 - 25 = 24
24 = 24
the answer is good
Which shows an equation in point-slope form of the line shown?
y−4=43(x−2)
y−2=34(x+6)
y−4=34(x−2)
y+2=43(x+6)
Number graph ranging from negative ten to ten on the x and y axes. A line passes through the labeled points (negative six, negative two) and (two, four).
Answer: Option (3)
Step-by-step explanation:
The slope of the given line is
[tex]\frac{-2-4}{-6-2}=\frac{-6}{-8}=\frac{3}{4}[/tex]
Thus, the answer must be Option (3)
Question 7 of 12, Step 1 of 2
6/19
Correct
If you throw exactly one head in two tosses of a coin you win $9. If not, you pay me $15.
Step 1 of 2: Find the expected value of the proposition. Round your answer to two decimal places. Losses must be expressed as negative values.
Answer
Step-by-step explanation:
the expected value is calculated by multiplying each of the possible outcomes by their probability, and then summing up all these results.
tossing a coin 2 times gives us 4 possible different outcomes (all with the same probability of 0.25) :
head - tail
head - head
tail - head
tail - tail
to have exactly one head is 2 out of these 4 possible outcomes, and the probability is 0.5.
everything else is also 2 out of these 4 possible outcomes, and the probability for that is therefore 0.5 too.
the expected value (from your point of view) is
9×0.5 - 15×0.5 = -$3.00
12. Of two inlet pipes, the smaller pipe takes four hours longer than the larger pipe to fill a
pool. When both pipes are open, the pool is filled in three hours and forty-five minutes. If
only the larger pipe is open, how many hours are required to fill the pool?
Answer:
6 hours
Step-by-step explanation:
Let the smaller pipe fill the pool in x hours and the bigger pipe y hours.
x-y=4
1/x+1/y=4/15
x=10, y=6
so 6 hours
Step-by-step explanation:
l = large pipe
s = small pipe
s needs x hours alone to fill the pool.
l needs x-4 hours alone to fill the pool.
s does 1/x of the work in 1 hour.
l does 1/(x-4) of the work in 1 hour.
3 hours 45 minutes = 3.75 hours
3.75 × 1/x + 3.75 × 1/(x-4) = 1 (= the whole work)
3.75 + 3.75 × x/(x-4) = x
3.75×(x-4) + 3.75×x = x(x-4) = x² - 4x
3.75x - 15 + 3.75x = x² - 4x
7.5x - 15 = x² - 4x
-15 = x² - 11.5x
0 = x² - 11.5x + 15
the general solution to such a quadratic equation is
x = (-b ± sqrt(b² - 4ac))/(2a)
in our case
a = 1
b = -11.5
c = 15
x = (11.5 ± sqrt(132.25 - 4×1×15))/(2×1) =
= (11.5 ± sqrt(72.25))/2 = (11.5 ± 8.5)/2
x1 = (11.5 + 8.5)/2 = 20/2 = 10
x2 = (11.5 - 8.5)/2 = 3/2 = 1.5
x = 1.5 would turn l = 1/(x-4) negative, which does not make sense.
so, x = 10 is our solution.
that means
s does 1/10 of the work in 1 hour.
so, the small pipe alone fills the pool in 10 hours.
l does 1/(10-4) = 1/6 of the work in 1 hour.
so, the large pipe alone fills the pool in 6 hours.
On that question regarding adding up different amounts of time you came to the conclusion the answer was 7.825. How much time is .825?
The time 0.825 is 49.5 minutes based on the conclusion that the sum of the different amounts of time was 7.825 hours.
What is the proportion in time?Proportion in time refers to the relationship between two or more ratios or quantities expressed in time measurements.
Data and Calculations:One hour = 60 minutes
One minute = 60 seconds
0.825 of an hour = 49.5 minutes (0.825 x 60 minutes)
0.5 minutes = 30 seconds (0.5 x 60)
Thus, we can conclude that the total time involved is 7 hours, 49 minutes, and 30 seconds.
Learn more about time proportions at https://brainly.com/question/27817533
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